Device for preventing and counteracting the warping of woodwork such as doors



Oct. 8, 1929. REENS 1,730,782

DEVICE FOR PREVENTING AND COUNTERACTING THE WARPING OF WOODWORK SUCH AS DOORS Filed June 5, 1926 2 Sheets-Sheet l Oct. 8, 1929. M. A. REENS 1,730,782

DEVICE FOR PREVENTING AND COUNTERACTING THE WARPING 0F WOODWORK SUCH AS DOORS Filed June 5. 1926 2 Sheets-Sheet 2 Fig. 9.

m. ,4. Ream nwewrak Patented Oct. 8, 1929 UNITED STATES PATENT OFFICE MAX,AL EXANDER BEEN S, OF AMSTERDAM, NETHERLANDS DEVICE FOR PREVENTING AND-COUNTERACTING THE WARPING F WOODWORK SUCH.

. AS DOORS Application filed June 5, 1926, Serial No. 113,920, and in the Netherlands October 7, 1925'.

steeped in water and dried for a long time and has almost completely ceased working, that is to say, which no longer warps. Moreover attempts have been made to guard as far as possible against the Warping of wooden structures by special constructions.

The use of wood that has almost completely ceased working is expensive, while even in the case of using the same in special constructional forms, the wood nevertheless still often warps in consequence of special circumstances, as for example by exposure to unequally distributed excessive heating. If the woodwork has already warped or twisted, experience has shown that it is adifl'icult and expensive matter to make it accurately flat again.

The present invention relates to means for restricting the warping of woodwork, such as doors, panels, partitions and the l1ke, and for straightening these articles again when warped; and the object of the invention is to enable fiat woodwork to be manufactured even from material that has not worked itself out, in which case the warping and twisting thereof is limited and it can be flattened again in a very simple manner, in the event of it warping at all.

The invention consists in that in the Woodwork which is to be kept flat, bars, strips or plates, preferably of metal, such as iron or copper, are either let into or otherwise connected therewith, and these bars, strips or plates are preferably adjustably connected with one another so that the bars, strips or plates exert upon the woodwork straightening forces, adjustable in magnitude, and perpendicular to the plane of the woodwork.

Such a torque may be obtained according to the invention in a simple manner by providing the bars, strips or plates with a noncircular hole, and arranging through these holes a bar, the non-circular outer ends of which, fitting into the holes, are helically twisted in opposite directions to one another.

Now if the connecting bar is driven in its longitudinal direction through the holes a torsional stress arises in this bar, the moment of which is counterbalanced b the moments of the forces exerted upon t e woodwork. Now the torsional moments exerted upon the woodwork are utilized for the straightening of warped woodwork, while the presence of an accurately fitting device in a wooden article counteracts the warping from the outset. The forces exerted upon the woodwork can 'be increased or diminished at will by displacing the torsion bar to a greater or less extent in its longitudinal direction.

According to the invention it is also possible to use strips, bars or plates which are formed integral with the connecting bar and to use strips formed of one piece and bent. The sides of thesestrips which originally lie in one plane are twisted in relation to one another, so that a permanent change of form isproduced and by placing the twisted strip round the warped woodwork the correcting forces are produced so that on untwisting the strip the woodwork is flattened.

Obviously it is possible to apply the main idea of this invention in various ways. Instead of the two bars or strips adjustably connected with one another it is possible to use a single bar or a single strip which is removably connected on two or more sides of the woodwork. By twisting the bar or strip the desired forces may be obtained for keeping or making the article flat, since after the twisting, by which the article is subjected to a torsional stress beyond its elastic limit, the bar or strip is rotated back again into its original plane and secured to the woodwork.

Several examples of the construction are illustrated in the accompanying drawings.

Figures 1, 7, 8 and 9 illustrate one constructional form and in which Figures 7, 8 and 9 are enlarged views of the iron strip 1 and the end of bar 2.

In Figure 1 is shown in front elevation a door, to the shorter sides of which iron strips 1 have been firmly screwed. On one of the longer sides of the door, in this case on the hinge side, is provided a groove, in which is arranged a bar 2. The quadrangular outer ends 3 and 4 of the bar 2 fit into corresponding quadrangular holes in the outer ends of the strips 1, and are helically twisted in such a way that the quadrangular outer end 4 for example exhibits a left-handed screw thread and the end 3 a right-handed thread, preferably of the same pitch. If the bar 2 is shifted a little in its longitudinal direction, by a blow with a hammer upon one of its outer ends for example, the outer ends 3 and 4 are driven through the holes in the strips 1 and therefore exert at the same time opposite torsional moments upon the said holes. There is thus roduced a torsional stress in the bar, which 1s transmitted at the outer ends 3 and 4, by

means of the strips, to the opposite door posts. It is clear that in this way a means is obtained for twisting the warped door flat again, while it is also intelligible that a door reinforced by the iron strips 1 and by the connecting bar 2 willbe less easily warped than an unprotected door. It is of course also possible to let the strips 1 into grooves in the door without other fastening, or to lodge them on the inner side of one of the door posts.

Figure 2 shows another constructional form of the strips 1. The strip is'here bent inwards, and the quadrangular aperture for the passage of the helical outer end 3 of the bar 2 is located in the bent part 5. Now the bar 2 may be actuated through a hole 6, and the door surface thereby bent straight. Instead of this a wedge 7 (shown dotted) may be utilized for the drivin The invention likewlse renders it possible to displace the bar 2 in its longitudinal direction by the aid of a screw thread and a nut. Figure 3 illustrates one example of this arrangement. On part of the bar 2 a screw thread is cut, and round this there screws a nut 8, which can be turned round by means of a steel pin fitting into the holes 9 for ex-,

ample, and which is embraced by the woodwork of the door in such a way that the door, though it can still turn, cannot become longitudinally displaced relatively to the nut. This means for shifting the bar 2 admits of course of finer adjustment than that of the constructional examples mentioned at the beginning.

In Figure 4 is illustrated an application of this invention in which the strips 1 are bent over and are so long that their bent-over outer ends almost touch one another. Now these quadrangular outer ends 10 and 11 are helically twisted and passed through a sleeve 12, also rovided with quadrangular holes. By now riving the sleeve in its longitudinal direction with a wedge or a nut, there are again produced therein opposite torsional moments which are counterbalanced by the torsional moments which the twisted strips 1 and ,2 exert thereon.

In Figure 5 is shown a further set of strips, F

the outer ends 13 and 14 of which lie outside the surface of the woodwork to be flattened. By moving these outer ends towards or away from one another the desired transmission of torsional moments can be effected by means of the strips 1.-

The example of Figure 6 shows bent-over bars or strips 1, the twisted outer ends of which are passed through a guiding piece 15, in the lateral edge of which an aperture is made in which a pin 16 is arranged. An iron pressure piece 1 is fitted loosely into the woodwork and is likewise provided with a pm 18. By the aid of a lever 19 (shown dotted in Figure 6), which can be inserted above or below the pin 18, the guiding piece 15 can be forced in the desired direction, and the $1311.18 1 thereby twisted in the desired direc- Instead of the quadrangular outer ends 3 and 4, other non-clrcular outer ends may be employed, which can be pushed through corresponding apertures in the strips 1. It is also possible, if desired, to construct only one outer end of; the bar 2 with a helical twist, and to keep the other end straight.

The sleeve construction illustrated in Figure 4 may also be executed in duplicate, that is, with two U shaped bent over bars 1 and it is also possible to construct the strips 1 if desired in a continuous strip.

Instead of connecting the strips 1 at their outer ends by the bar 2, the bar 2 may according to the invention be secured at other places to the strip 1, whilst also more than one connesting bar 2 may be employed.

It is also possible to employ this invention on subdivisions of plane surfaces, for example on that of the panels of a door or the like.

The invention is not limited to woodwork only, but can be employed for any other materal that is subject to warping.

- What I claim is 1. Apparatus for restricting the warping of woodwork such as doors, panels, partitions and the like and for straightening such articles when Warped, comprising bars firmly connected to said woodwork in the neighbourhood of two opposite edges thereof, a member movable longitudinally in a direction perpendicular to the two opposite edges of the woodwork to which said bars are connected, said bars and said longitudinally ing of woo Apparatus for restricting the warping of woodwork such as doors, panels, partitions and the like and for straightening such articles when warped, comprising bars firmly connected to said woodwork in the neighbourhood of two opposite edges thereof, a member movable longitudinally in a direction perpendicular to the two opposite edges of the woodwork to which said bars are connected, said bars and said longitudinall movable member being adapted to co-act wlth one another by means of two non-circular extremities, engaging through two corresponding non-circular holes, one of the two said noncircular extremities being helically twisted, in such a manner as to exert upon said woodwork equal butoppositely directed forces, adjustable in magnitude, perpendicular to the surface of said woodwork.

3. Apparatus for restricting the warping of woodwork such as doors, panels, partitions and the like and for straightening such articles when warped, comprising bars firmly connected to said woodwork in the neighbourhood of two opposite edges thereof, said bars being formed with non-circular holes in their outer ends, a rod having non-circular ends adapted to fit into said non-circular holes, the two said non-circular ends being helically twisted in opposite directions, in such a manner as to exert upon said woodwork equal but oppositely directed forces, adjustable in ma itude, perpendicular to the surface of sai woodwork.

4. Ap aratus for restricting the warping of woo work such as doors, panels, partitions and the like and for straightening such articles when warped, comprising bars connected to said woodwork in the neighbourhood of two edges thereof, adjacent ends of said bars being bent round towards one another along a third side of said woodwork, the adjacent ends of said bars having noncircular ends helically twisted in opposite directions, a member having non-circular holes in its ends into which the non-circular ends of said bars fit, and meansfor displacing said member longitudinally in relation to the helically twisted portions of the bars.

'5. An ap aratus for restricting the warpwork, such as doors, panels, partitlons and the like, and for straightening such articles when warped, including a device composed of relativel displaceable portions secured to said woo work at two opposite sides thereof and havin a portion extending along a third side of sai woodwork, the latter portion having angular parts adapted. to be acted upon to exert opposltely directed forces upon the displaceable portions and said w00dwork.

In testimony whereof I have signed my name to this specification.

MAX ALEXANDER REENS. 

